Fluid motor



: May 3, 1966 J. T. ELLIS, JR 3,249,018

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United States Patent 3,249,018 FLUID MOTOR John T. Ellis, Jr., Des Plaines, Ill., assignor to Ellis Fluid Dynamics Cor-1)., Skokie, Ill., a corporation of Illinois Filed July 17, 1963, Ser. No. 295,640 28 Claims. (Cl. 91-44) This invention relates to an improved construction for a cylinder, and more particularly, to an improved construction for a cylinder which is automatically locked in a predetermined position which look. may be readily released by application of fluid pressure which operates the cylinder and which construction allows for a positive motion of a piston to one end of the cylinder upon interruption of fluid under pressure to the cylinder.

The use of fluid operated cylinders as remote control devices, or more specifically, as fluid motors has achieved a wide degree of acceptance. In certain applications, it is desirable for a cylinder to be locked in a preselected position. Many devices are provided to accomplish this result. However, the release of the cylinder after it is securely locked presents additional problems. It is apparent that various means may be provided in which extra lines are provided to unlock the cylinder by a separate operator action. It is, also, apparent that arrangements of this type are expensive to manufacture and expensive to maintain. It is, therefore, a principal object of this invention to provide a fluid operated cylinder which has an inexpensive locking device formed integral with the cylinder which look is released by the operation of fluid pressure which, also, operates the cylinder.

It is another object of the present invention to provide a cylinder construction which provides for moving the cylinder piston to a predetermined position upon interruption of the fluid pressure to the cylinder.

It is a further object of the instant invention to provide a cylinder construction which allows the cylinder to have its piston rapidly moved to a predetermined position, but the piston has a means for deceleration as it approaches the end of its travel.

Another object of the herein disclosed invention is to provide a fail safe cylinder construction which allows the cylinder to assume a predictable attitude upon failure of fluid pressure to the cylinder which cylinder will be locked in a preselected position.

It is a still further object of the present invention to provide a cylinder construction which is economical to manufacture and has a high degree of reliability.

Other objects and uses of the herein disclosed invention will become readily apparent to those skilled in the art upon a perusal of the following specification in light of the accompanying drawings in which:

FIGURE 1 is a partial cross-sectional view and a partial diagrammatic view showing an installation in which a cylinder embodying the present invention is used to operate a door or valve;

FIGURE 2 is a partial cross-sectional view of the cylinder shown in FIGURE 1;

FIGURE 3 is a cross-sectional view taken on line 33 of FIGURE 2;

FIGURE 4 is a fragmentary cross-sectional view of a portion of the cylinder shown in FIGURE 2 and taken on line 44 of FIGURE 3 showing the cylinder in a rest or lock position;

FIGURE 5 is a fragmentary cross-sectional view of the 3,249,018 Patented May 3, 1966 cylinder shown in FIGURE 4, but with the cylinder shown in an unlocked attitude;

FIGURE 6 is a fragmentary cross-sectional view of a portion of the cylinder shown in FIGURE 4 showing a piston moving toward a head;

FIGURE 7 is a cross-sectional view taken on line 7-7 of FIGURE 4;

FIGURE 8 is an enlarged fragmentary cross-sectional view taken on line 88 of FIGURE 3 showing in detail a fluid flow path through the cylinder head;

FIGURE 9 is substantially identical to FIGURE 8 but showing a valve in a discharged attitude; and

FIGURE 10 is a plan view of the top of the valve shown in detail in FIGURES 8 and 9.

Referring now to the drawings and especially to FIG- URE l, a base foundation 10 is shown in a fragmentary view with a liner 12 mounted in an opening in the foundation. Attached to the liner is a valve seat 14 which has a gasket 15 mounted on one face adjacent to its periphery. An operator tube 16 is positioned in the central portion of the seat and the operator tube is supported therein by webs 18. An operator flange 20 is mounted on tube 16. A cylinder 22, embodying the herein disclosed invention, is attached to flange 20 by a plurality of screws 23. The cylinder includes a rod 24 which is slideable through the flange 20 and has a door or valve 26 mounted on its outer-most end. The door has a spring block 28 fixed to it with a compression spring 30 extending between the spring block and the flange 20.

In this instance, the cylinder 22 is a pneumatic cylinder which is operated by air under pressure. The cylinder 22 includes a cylinder valve 32 which is connected to a threeway valve 34 by a pipe 35. The three-way valve is connected to a manual pump 36 through a ball check valve 38 and to a motorized pump 40 through a valve 42, an accumulator 44 and a second ball check valve 46.

Looking now to FIGURE 2, it may be seen that the cylinder includes a tube 48 which has a head 50 attached to one end as is evident in FIGURE 1. Head 50 is secured to the mounting flange 20 by the plurality screws 23. The other end of the tube has a head 54 sealingly attached thereto. The heads are secured to the tube by conventional tie bolts 56. Slidea-bly mounted in the tube is a piston 58. The piston has a groove 60 with an O-ring 62 mounted therein so that the piston is sealingly connected to the interior surface of the tube. The piston 58 is threadedly connected to one end of the rod 24 which rod is axially movable in head 59.

The head 54 contains an axial aperture 64 with a radial aperture 66 opening into the axial aperture and connecting the interior of the tube with the valve 32. The axial aperture 64 includes a reduced portion 68 for reasons which will become apparent hereinafter.

Looking now to FIGURE 4, it may be seen that a spring rod 70 has one end thre-adedly connected to the rod 24 and a set-screw 72 prevents loosening of the rods. The spring rod has a cushion reduction portion 74 adjacent to the rod 24, which portion 74 has a cushion sleeve 76 mounted thereon. The cushion sleeve 76 is cooperative with the reduced portion 68 of the axial aperture to cushion the piston 58 as it approaches head 54. The spring rod 70 includes an annular lock 78 which is cooperative with a rod lock, generally indicated by numeral 80, in a manner which will be described in detail hereinafter. A spring plate 82 is connected to the spring rod 70 in a conventional manner. A compression spring 84 is positioned in engagement with the spring plate 82 and the head 54 so that the spring 84 constantly urges the piston 58 toward the head 54. A spring cover 86 is secured to the head 54 by bolts 88 in order to cover the spring and the spring rod.

The construction of the rod lock 80 is clearly shOWn in FIGURES 4 through 7. The rod lock includes an annular ball stop 90 which is positioned in engagement with the head 54. It is apparent that the spring rod 70 is free ,to slide through the annular ball stop and that there is a considerable space between the ball stop and the spring rod to allow fluid to flow therebetween. The ball stop is held in position by a lock tube 92 which is in sealing engagement with the head 54 in that a seal 94 is positioned between the end of the lock tube 92 and the head 54. Welded to the lock tube is a lock tube flange 96 which has a plurality of bolts 98 securing the fiangeto head 54. The lock tube is concentric with the spring rod 7 A lock sleeve stop 100 is positioned inside the lock tube, and the stop 100 is held in one direction by a snap-ring 102. The stop 100 has a seal 104 mounted in its interior surface for engagement with the spring rod 70. A spacer sleeve 106 is mounted inside the tube 92 and adjacent to the stop 100. Positioned between the spacer sleeve 106 and the 'ball stop 90 is a lock sleeve or lock piston 108. The lock sleeve 108 is slidable relative to the tube 92 and has an O-ring 110 mounted therein in sealing engagement with the tube 92 to form a seal therebetween. The sleeve has 'an O-ring 112 mounted in its interior surface so that the O-ring 112 is in sealing engagement with the spring rod 70. The spring rod may slide through the sleeve and still have a seal therebetween for reasons which will become apparent hereinafter. The sleeve 108 has a chamfered annulus 114 formed integral at one end which annulus 114 is engageable with twelve lock balls 116. The annulus 114 is enlarged to receive and to hold the balls 116 when the balls are positioned in the lock groove 78. A lock spring 118 is mounted between the stop 100 and the sleeve 108 constantly urging the sleeve toward the ball stop 90 and into engagement with the balls 116.

Looking now to FIGURES 8 through 10, the construc+ tion of the cylinder valve 32 is clearly shown therein. The cylinder valve 32 includes a valve sleeve 120' which has a plurality of discharge ports 122 on the end adjacent to the head 54. A valve body 124 is slideably mounted in the sleeve 120. The valve body includes a sealing groove 126 which has an O-ring 128 mounted therein and in sealing engagement with the interior of the valve sleeve 120.

'The valve body contains an axial aperture 130 which provides a fluid flow path through the valve body. The axial aperture contains a restricted portion 132 which has a ball 134 sealably mounted therein. The ball 132 has a spring 136 constantly urging the ball into engagement with the restricted portion 132. The spring is in engagement with a washer 138 which is held in position by a snap-ring 140. The valve body has a seal 142 mounted in one end which seal is engageable with the head 54 to form a seal therebetween. At the other end of the sleeve 120, there is a top 144. The top includes an O-ring 146 which provides a seal between the top and the sleeve 120. A plurality of screws 148' are positioned in the top and are mounted in the head 54 to hold the valve in place and to hold the top in sealing engagement with the valve sleeve. The top 144 contains an aperture 150 which provides a fluid flow path to pipe 35 which isconnected to valve 34. A spring 154 is mounted in the aperture 130 and in engagement with the top 144 in order to urge constantly the valve body into a sealing engagement with the head 54.

In the normal operation of the instant device, pneumatic pressure is generated in the pump 40 to displace the check valve 46. The pressure builds up in accumulator 44, and the air flows through valve 42 and then through valve 34. The air under pressure flowsthrough pipe 35 into the cylinder valve or dump valve 32. The air under pressure applies a force to the upper portion of the valve body. It may be noted that there is a difierential area between the upper portion of the valve body 124 and the lower portion, that is, the portion in engagement with the cylinder head 54, inasmuch as the cylinder head 54 has a seal 142 which is substantially smaller in diameter than the upper portion of the head. Furthermore, it may be noted that the spring 154, also, provides a force to keep the valve body in engagement with the cylinder head. The air pressure displaces the ball 134 against the force of spring 136 so that the air then enters the radial aperture 66. The air under pressure flows into the axial aperture 64 and the air under pressure applies a force to the piston 58. It should be noted at this point that the piston 58 is locked into a predetermined position by the balls 116 which are positioned in lock groove 78. The balls are held in position by the sleeve 108. As the pressure builds up in the axial aperture 64, a force is applied to the end of the-sleeve 108 which is adjacent to the head 54. When suflicient pressure is built up the pressure overcomes the force of spring 118 to move the sleeve 108 to the right as viewed in FIGURES 4, 5, 6, 8, and 9. Once the sleeve 108 is moved to the right, it engages the spacer 106 and the sleeve then assumes the attitude shown in FIGURE 5. As the pressure continues to build up in the tube 48, a force is applied to the piston 58 to move the piston to the left. The piston is moved to the left, and the balls 116 are forced out of the groove 78 inasmuch as the balls in the groove engage the stop 90. It should be noted that the pressure in the tube must be of a sufficient magnitude to overcome the force of spring 84. As the piston 58 moves toward the head 50, the valve or door 26 is moved away from the seat 14 and seal 15. The piston then comes into engagement with head 50, which head, also, acts as a stop means for the piston. It should be noted that the valve or door 26 is held in an open position by the fluid pressure developed by the pump 40. It may be further noted that in the event that the mechanized pump 40 should break down, a hand operated pump 36 may be used to open the door 26. That is, the pump 36 is operated thereby displacing ball check valve 36 and fluid pressure is delivered to pipe 35 through the valve 34.

When it is necessary to close the valve 26, the pump 40 is interrupted in its normal operation. The pressure in the pipe 35 thereby drops. This drop may, also, be accomplished by opening valve 34 to the atmosphere. By either operation, the result is that there is substantially greater pressure in the tube 48 than there is in the pipe 35. This dilferential pressure closes the ball check valve in the valve body, that is, the ball 134 is placed into sealing engagement with the valve body and the differential pressure causes the valve body 124 to be displaced from the cylinder head 54. Once the valve body is shifted away from the cylinder head and the seal is broken, the air is expelled through the discharge ports 122 to the atmosphere, that is, the air flows out through the radial aperture 66.

With a decrease in pressure, the return spring 84 applies a force to the spring plate 82 to the right thereby pulling the piston 58 toward the head 54. As thepiston 58 moves to the right, the air is expelled through the dump valve. When the piston approaches the head 54, the sleeve 76'enters the restricted aperture 68, thereby restricting the flow of fluid out of the tube 48, that is, from the space between the piston 58 and the head 54. The piston is cushioned as it approaches the head. Once the piston reaches its fur'thermost position in engagement with the cylinder head 54, the balls 116 drop into the lock groove 78 and the sleeve 108 slides to the left by the action ofthe lock spring to lock the balls into position. Thereby, locking the piston into a position which is to its furthest right, also, closing the opening in the valve seat 14. It should be'noted that the piston is firmly locked into position. The piston cannot move to the right since it is in engagement with the head 54. The piston is prevented from moving to the left because the balls engage stop and they must be expelled radially in order to allow the rod to move, but the annulus 114 prevents radial expulsion of the balls.

It may be appreciated that through a force may tend to pull the door 26 away from the valve seat 14, the locking of the cylinder prevents a pulling open of the door. There is a firm lock which prevents the door from being opened.

It may, also, be noted that the instant construction provides a device which causes the door 26 to close when the pressure fails in pipe 35, thus there is a fail safe provision in the instant construction.

Although a specific embodiment of the instant invention has been shown and described in detail above, it is apparent that those skilled in the art may make various modifications and changes without departing from the spirit and scope of the present invention. It is to be expressly understood that the instant invention is limited only by the appended claims.

What is claimed is:

1. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having a flow path for a fluid therethrough, a valve sleeve having one end connected to the first head in communication with the flow path in said head, said valve sleeve having an escape port in one end adjacent to the first head, a valve top sealingly engageable with the other end of the valve sleeve, said valve top having an aperture containing therein for connection to a fluid source, a sliding valve body sealingly and slideably mounted in the valve sleeve, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a seal mounted in one end of the sliding valve body sealingly engageable with the first head, a spring mounted in the valve sleeve urging the valve body into sealing engagement with the first head, a spring loaded ball check mounted in the valve body to prevent flow of fluid in a direction from the first head toward the valve top, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod having one end connected to said piston and being axially movable in said axial aperture of the first head, said rod having an annular lock groove formed in its outer periphery, a lock tube fixed to the first head and being concentric with the rod, a lock sleeve sealingly and slideably engaging the rod and sealingly and slideably engaging the lock tube, a plurality of lock balls in en gagement with the rod and being positionable in the annular lock groove to be locked in said groove by the lock sleeve, a lock sleeve stop mounted Within the lock tube and being held in one direction, and a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head, whereby fluid under pressure enters the valve top and displaces the ball check in the valve body to flow through the axial aperture in the valve body and pass through the fluid flow path of the first head to apply a force to the lock sleeve to disengage the lock balls and to apply a force to the piston to move the piston and rod relative to the head, and release of the pressure allows pressure built up in the tube to close the ball check valve and to move the sliding valve body relative to the valve sleeve to allow fluid to exhaust through the exhaust port.

2. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having a flow path for a fluid through said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod connected to said piston and extending through the axial aperture of the first head, a cushion sleeve connected to said piston and being cooperative with the flow path in the first head to cushion the piston as it reaches the end of its stroke toward the first head, said rod having an annular lock groove formed in its outer periphery, a

plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slideably engaging the rod and being engageable with the balls to hold the balls in the annular lock groove, a lock tube being concentric with and sealingly engageable with said lock sleeve and being fixed to the said head, a lock sleeve stop mounted within the lock tube and being held in one direction, and a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head.

3. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted, on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a valve sleeve mounted on the first head in communication with the aperture, said valve sleeve an escape port adjacent to the first head, a sliding valve body sealingly and slideably mounted in the valve sleeve, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a seal mounted on one end of the body for sealing engagement with the first head, means mounted in the valve body to prevent flow of fluid through the axial aperture in said valve body in a direction away from the first head, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a rod connected to the piston and being axially movable in one of said heads, a rod lock, connnected to said rod for locking said rod in one position, said rod lock being releasable by the application of fluid pressure.

4. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end in said tube, sai'd first head having an aperture contained the-rein providing a fluid flo w path between the interior and exterior of the tube, a valve connected to said first head for connecting a source of fluid to the aperture in said head and to allow fluid to discharge from the tube when fluid pressure inside the tube is substantially greater than the fluid pressure of the source of the fluid, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a rod connected to the piston and being axially movable in one of said heads, and a rod lofok connected to said rod for locking said rod in one position, said rod lock being releasable by the application of fluid pressure which simultaneously releases the look and rnoves said piston.

5. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a cushion plunger connected to said piston and cooperative with one of said heads to cushion the piston as it approaches said head, a rod connected to the piston and being axially movable in one of said heads, a rod loc'k connected to said rod for looking said rod in one position, and means connected to said rod lock and being operable by fluid pressure to release said rod lock.

6. A fluid ope-rated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing :a fluid flow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a return spring positioned outside of the tube and being connected to the piston for constantly urging the piston toward one of said heads, and a lock for connection to the piston for holding the piston at 'a predetermined position and said look being releasalble by the application of fluid pressure to release simultaneously said lock .and to move the piston.

l 7. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a rod being axially movable in one of said heads, a rod look connected to said rod [for looking said rod in one position, a piston sealingly and slideably mounted in the tube and being connected to one end of said rod, a return spring positioned outside of the tube and being connected to the piston tor constantly urging the piston toward one of said heads, and a cushion plunger connected to said piston and cooperative with one of said heads to cushion the piston as it approaches said head.

8. A fluid operated cylinder comprising, in combinations, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a valve connected to said first head for-connecting a source of fluid to the aperture in said head and to allow fluid to discharge from the tube when fluid pressure inside the tube is substantially greater than the fluid pressure of the source or fluid, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a rod connected to the piston and being axially movable in one of said heads, a return spring positioned outside of the tube and being connected to the piston for constantly urging the piston toward one of said heads, and a rod lock connected to said rod for locking said rod in one position.

9. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a cushion plunger connected to said piston and cooper: ative with one of said heads to cushion the piston as it approaches said one head, a return spring positioned outside of the tube and being connected to the piston tor constantly urging the piston toward one of said heads, and a rod connected to the piston and being axially movable in one of said heads.

10. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a cushion plunger connected to said piston and cooperative with one of said heads to cushion the piston as it approaches said head, a valve connected to said first head for connecting a source of fluid to the aperture in said head and to allow fluid to discharge from the tube when fluid pressure inside the tube is substantially greater than the fluid pressure of the source of the fluid, a rod connected to the piston and being axial-1y movable in one of said heads, and a rod lock connected to said rod for for locking said rod in one position, said rod lock being releasable by the application of fluid pressure.

11. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid fiow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a piston seal-ingly and slideably mounted in the tube and being movable between the heads, a valve connected to said first head for connecting nected to the piston and being axially movable in one 7 of said heads, and a return spring positioned outside of the tube and being connected to the piston for constant-1y urging the piston toward one of said heads.

12. Afluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a valve sleeve mounted on the first head communicating with the aperture, said valve sleeve having an escape port adjacent to the first head, a sliding valve body sealingly'and slideably mounted in the valve sleeve, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a seal mounted in one end of the body for sealing engagement with the first head, means mounted in the valve body to prevent flow of fluid through the valve body in a direction away from the first head, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a rod connected to the piston and being axially movable in one of said heads, and a rod lock connected to said rod for locking said rod in a selected position.

13. A fluid operated cylinder comprising, in combination, a tube a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a valve sleeve having one end connected to the first head for communicating with the aperture in said head, said valve sleeve having a discharge port in the end adjacent to the first head, a sliding valve body sealingly and slideably mounted in the valve sleeve, said valve body having an axial aperture contained therein to allow fluid to flow through the body, means connected to said valve body to interrupt the flow of fluid through the valve body in a direction away from the first head, a sealing member on the end of the valve body adjacent to the end of the sleeve having the discharge port sealingly engageable with the first head, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, and a rod connected to the piston and being axially movable in one of said heads.

14. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a valve connected to said first head for connecting a source of fluid to the aperture in said head and to allow fluid to discharge from the tube when fluid pressure inside the tube is substantially greater than the fluid pressure of the source of fluid, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a rod connected to said piston and being axially movable in one of said heads, said rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slideably engaging the rod and being engageable with the balls to hold the balls in the annular lock groove, a lock tube being concentric with the lock sleeve and being sealingly engageable with the lock sleeve, said lock tube being fixed to one of said heads, a lock sleeve stop mounted within the lock tube and being held in one direction, and a lock sleeve positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the balls.

15. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained therein providing a fluid flow path between the interior and exterior of the tube, a valve connected to said first head for connecting a source of fluid to the aperture in said head and to allow fluid to discharge from the tube when fluid pressure inside the tube is substantially greater than the fluid pressure of the source of fluid, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a return spring positioned outside of the tube and being connected to the piston for constantly urging the piston toward one of said heads, a cushion plunger connected to said piston and cooperative with one of said heads to cushion the piston as it approaches said head, a rod connected to the piston and being axially movable in one of said heads, said rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slideably engaging the rod and being engageable with the walls to hold the balls in the annular lock groove, a lock tube being concentric with and sealingly engageable with said lock sleeve and being fixed to one of said heads, a lock sleeve stop mounted within the lock tube and being held in one direction, and a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the balls.

16. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture therein to provide a flow path for a fluid through said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod connected to said piston and being axially movable through one of said heads, said rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slideably engaging the rod and being engageable with the balls to hold the balls in the annular lock groove, a lock tube being concentric with the lock sleeve and being slideably engageable with said lock sleeve, a lock sleeve stop mounted within the lock tube and being held in one direction, a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the lock balls, and a sleeve spacer positioned between the lock sleeve and the lock stop to limit the movement of the lock sleeve.

17. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having a fiow path for a fluid through said head, a second head mounted on the other end of said tube, a piston sealingly and slidably mounted in said tube and being axially movable between said heads, a rod connected to the piston and being axially movable in the first head, a spring plate fixed to the rod, a compression spring mounted in engagement with the spring plate and the first head to urge constantly the piston toward the first head, said rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slidably engaging the rod and being engageable with the balls to hold the balls in the annual lock groove, a lock tube being concentric with the lock sleeve and being sealingly engageable with said lock sleeve fixed to the first head, a lock sleeve stop mounted within the lock tube and being held in one direction, and a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head, whereby positioning of the annular grove in the rod adjacent to the ball stop allows the lock balls to fall into said groove and to 10 be held therein by the lock sleeve, and the rod is unlocked by applying pressure to the lock sleeve against the force of the lock spring to retract the lock sleeve and the same pressure simultaneously urges the piston to move and carry with it the rod.

18. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture in the central portion thereof to provide a flow path for a fluid through said head and a second aperture communicating with the axial aperture and extending to the outer periphery of said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod connected to said piston, a cushion sleeve connected to said piston and being cooperative with the axial aperture to cushion the piston as it moves toward the first head, a spring plate fixed to the rod, a compression spring mounted in engagement with the spring plate and the first head to urge constantly the piston toward the first head, said rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the spring rod and being positionable in the annular lock groove, a lock sleeve spaced from said first head sealingly and slideably engaging the rod and being engageable with the balls to hold the balls in the annular lock groove to lock said rod in one position, a lock tube fixed to the first head being concentric with the lock sleeve and being sealingly engageable with the lock sleeve, a lock sleeve stop mounted within the lock tube and being held in one direction, and a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head, whereby the lock balls are disengaged from the annular lock groove to release the rod by the application of fluid pressure to the lock sleeve to displace the sleeve against the lock spring and the same fluid pressure moves the piston to move the rod and disengage the rod from the lock balls.

19. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture in the central portion thereof to provide a flow path for a fluid through said head and a radial aperture communicating with the axial aperture and extending to the outer periphery of said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod connected to said piston and extending through one of said heads, a spring plate fixed to said rod, and a compression spring mounted in engagement with the spring plate and one of said heads to urge constantly the piston toward that head.

20. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture in the central portion thereof to provide a flow path for a fluid through said head and a radial aperture communicating with the axial aperture and extending to the outer periphery of said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a piston rod having one end connected to said piston and having the other end axially movable in the second head, a spring rod having one end fixed to the piston rod and being axially movable in the axial aperture of the first head, a spring plate fixed to the other end of the spring rod, a compression spring mounted in engagement with the spring plate and the first head constantly urging the piston toward the first head, and a cushion sleeve fixed to the spring rod and being cooperative with the axial aperture in the first head to cushion the piston as it moves toward the first head.

21. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said first head having an aperture contained c 11 i V therein providing a fluid flow path between the interior and exterior of the tube, a second head mounted on the other end of the tube, a piston sealingly and slideably mounted in the tube and being movable between the heads, a rod connected to the piston and being axially movable in one of said heads, a valve connected to said first head for connecting a source of fluid to the aperture in said head and to allow fluid to discharge from the tube when fluid pressure inside the tube is substantially greater than the fluid pressure of the source of fluid, a cushion plunger connected to said piston and cooperative with one of said heads to cushion the piston as it aproaches said head, a return spring positioned outside the tube and being connected to the piston constantly urging the piston toward one of said heads, a rod lock connected to said rod for locking said rod in one position, and means connected to said rod lock and being operable by fluid pressure to release said rod lock.

22. A fluid operated cylinder comprising, in combination, atube, a first head sealingly mounted on one end of said tube, said head having an aperture contained therein to provide a flow path for a fluid between the interior of the tube and the outer periphery of said head, a valve sleeve having one end connected to the first head and communicating with the aperture in said head, said valve sleeve having an escape port adjacent to the first head, a sliding valve body sealingly and slidably mounted in the valve sleeve, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid in a direction away from the head, a seal mounted in one end of the body for sealing engagement with the first head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod having one end fixed to said piston and being axially movable in the first head, a spring plate fixed to the other end of said rod, and a compression spring positioned between the spring plate and the first head to urge constantly the piston toward the first head.

23. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an aperture contained therein to provide a communicating path between the outer periphery of said head and the interior of said tube, a valve sleeve mounted on said head and having one end in communication with the aperture in said head, said valve sleeve having an escape port adjacent to the first head, a sliding valve body sealingly and slideably mounted in the valve sleeve, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid in a direction away from the first head, a seal mounted in one end of the body of sealing engagement with the first head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted on said tube and being axially movable between said heads, a cushion sleeve connected to the piston and being movable with said piston and being cooperative with the aperture in said first head to cushion the piston as it moved toward the first head at the end of its stroke, and a rod connected to said piston and being axially movable through one of said heads.

24. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture contained therein to provide a flow path in said head and a radial aperture communicating with the axial aperture and extending to the outer periphery of said head, a second head mounted on theother end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod connected to said piston and being axially movable in one of said heads,

a valve sleeve mounted on the first head having one end in communication with the radial aperture, said valve sleeve having a plurality of escape ports adjacent to the first head, a valve top sealingly engageable with the other end of the valve sleeve, said valve top having an aperture contained therein for connection to a fluid source, a sliding valve body sealingly and slideably mounted in the valve sleeve, a seal mounted in one end of the body for sealing engagement with the first head, a spring mounted in the valve sleeve urging the valve body into sealing engagement with the first head, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid in a direction from the first head toward the top, whereby fluid delivered to the top of the valve causes the ball check to unseat and a flow along the radial aperture into the axial aperture of the first head to apply pressure to the piston, and reduction of the pressure on the side of the valve adjacent to the top causes pressure built up in the piston to unseat the valve body from the first head and allow fluid to escape through the exhaust ports.

25. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture and a second aperture communicating with the axial aperture to provide a flow path to the interior of said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a valve sleeve mounted on the first head in communication with the second aperture, said valve sleeve having an escape port adjacent to the first head, a valve top sealingly engageable with the end of the valve sleeve spaced from the first head, said valve top having an aperture contained therein for connection to a fluid source, a sliding valve body sealingly and slideably mounted in the valve sleeve, a seal mounted on one end of the body for sealing engagement with the first head, a spring mounted in the valve sleeve urging the valve body into sealing engagement with the first head, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid in a direction from the first head toward the top, a cushion sleeve fixed to the piston and being cooperative with the axial aperture in the first head, to cushion the piston as it moves toward the first head, a rod connected to the piston and being axially movable in the first head, a spring plate fixed to the rod, and a compression spring mounted in engagement with the spring plate and the first head and to urge constantly the piston toward the first head, whereby fluid under'pressure enters the tube by passing through the valve top displacing the ball check and passing through the valve body, then into the second aperture and through the axial aperture ofthe first head, when the fluid pressure on the valve body is relieved the compression spring tends to move the piston toward the first head building up a pressure within the tube and causing the pressure to act on the valve body to move the valve body in the valve sleeve away from the first head, thereby breaking the seal and allowing the fluid to be expelled through the exhaust port in the valve sleeve.

26. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture in the central portion thereof to provide a flow path for a fluid through said head and a second aperture communicating with the axial aperture and extending to the outer periphery of said head, a valve sleeve having one end connected to the first head and communicating with the second aper ture of the first head, said valve sleeve having an escape port in one end adjacent to the first head, a valve top sealingly engageable with the other end of the valve sleeve, said valve top having an aperture contained there in for connection to a fluid source, a sliding valve body sealingly and slideably mounted in the valve sleeve, a seal mounted on one end of the body for sealing engagement with the first head, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid through the axial aperture in the valve body in a direction from the first head toward the valve top, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a cushion sleeve connected to said piston and being cooperative with the axial aperture in said first head to cushion the piston as it moves toward the first head, a rod connected to said piston and being axially movable in the axial aperture of the first head, said rod having an annular groove formed in its outer periphery, a lock tube fixed to the first head and being concentric with the rod, a plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slideably engaging the rod and the lock tube, said lock sleeve being engageable with the balls to hold the balls in the annular lock groove, a lock stop mounted Within the tube and being held in one direction, and a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head.

27. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having a how path for a fluid therethrough, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a rod fixed to said piston and being axially movable in the axial aperture of the first head, a spring plate fixed to the rod, a compression spring mounted in engagement with the spring plate and the first head to urge constantly the piston toward the first head, a valve sleeve mounted on the first head in communication with the radial aperture, said valve sleeve having an escape port in one end adjacent to the first head, a valve top sealingly engageable with the other end of the valve sleeve, said valve top having an aperture contained therein for connection to a fluid source, a sliding valve body sealingly and slideably mounted in the valve sleeve, a seal mounted in one end of the body for sealing engagement with the first head, a spring mounted in the valve sleeve urging the valve body into sealing engagement with the first head, said valve body having an axial aperture contained therein to allow fluid to flow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid through the valve body in a direction from the first head toward the valve top, said rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the rod and being positionable in the annular lock groove, a lock sleeve sealingly and slideably engaging the rod and being engageable with the balls to hold the balls in the annular lock groove to lock the rod against movement relative to the first head, a lock tube fixed to the first head being concentric with and sealingly engageable with the lock sleeve, a lock sleeve stop mounted within the lock tube and being held in one direction and a lock spring posi tioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head, whereby fluid under pressure displaces the ball check to flow through the second aperture and into the axial aperture of the first head to apply a pressure to the lock sleeve in order to displace the lock sleeve against the lock spring to release the lock balls from the annular lock groove, the pressure of the fluid urges the piston to move and to displace the lock balls from the annular lock groove, and reduction of the pressure on the top side of the valve body causes the ball check to close and pressure in the tube raises the valve body from engagement with the cylinder head to allow fluid to exhaust through the exhaust port.

28. A fluid operated cylinder comprising, in combination, a tube, a first head sealingly mounted on one end of said tube, said head having an axial aperture in the central portion thereof to provide a flow path for a fluid through said head and a radial aperture communicating with the axial aperture and extending to the outer periphery of said head, a second head mounted on the other end of said tube, a piston sealingly and slideably mounted in said tube and being axially movable between said heads, a piston rod having one end fixed to said piston and having the other end axially movable in the second head, a spring rod fixed to the piston rod and being axially movable in the axial aperture of the first head, a cushion sleeve fixed to the spring rod and being cooperative with the axial aperture to cushion the piston as it moves toward the first head, a spring plate fixed to the spring rod, a compression spring mounted in engagement with the spring plate and the first head to urge constantly the piston toward the first head, said spring rod having an annular lock groove formed in its outer periphery, a plurality of lock balls in engagement with the spring rod and being positionable in the annular lock groove, a ball stop mounted adjacent to the first head for preventing the movement of the balls in one direction, a lock sleeve seal ingly and slideably engaging the spring rod and being engageable with the balls to hold the balls in the annular lock groove, a lock tube being concentric with the lock sleeve and being sealingly engageable with said lock sleeve, said lock tube being fixed to the first head, a lock sleeve stop mounted within the lock tube and being held in one direction, a lock spring positioned between the lock sleeve and the lock stop constantly urging the lock sleeve toward the first head, a sleeve spacer positioned between the lock sleeve and the lock stop to limit the movement of the lock sleeve, a valve sleeve mounted on the first head in connection with the radial aperture, said valve sleeve having a plurality of escape ports adjacent to the first head, a valve top sealingly engageable with the upper portion of the valve sleeve, said valve top having an aperture contained therein for connection to a fluid source, a sliding valve body sealingly and slideably mounted in the valve sleeve, a seal mounted in one end of the body for sealing engagement with the first head, a spring mounted in the valve sleeve to urge the valve body into sealing engagement with the first head, said valve body having an axial aperture contained therein to allow fluid to fiow through the valve body, a spring loaded ball check mounted in the valve body to prevent flow of fluid in a direction from the first head toward the top, whereby fluid under pressure delivered to the top of the valve causes the ball check to unseat and flow along the radial aperture into the axial aperture where fluid pressure displaces the lock sleeve against the force of the lock spring to release the balls positioned in the annular lock groove, the fluid pressure enters the space between the piston head and the first head to move the piston head away from the first head and the balls are forced out of the annular lock groove, and release of the pressure at the top of the valve causes the return spring to urge the piston toward the first head to compress fluid in the cylinder between the piston and the first head and the pressure of the fluid raises the valve body to unseat the valve body from the first head and allow fluid to escape along the axial aperture through the radial aperture and out through the exhaust ports in the valve sleeve, as the piston approaches the first head, the cushion sleeve cooperates with the first head to cushion the piston as it approaches the end of its stroke, and the balls fall into the annular groove and are locked therein by the lock sleeve to hold the piston in a terminal position.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Engel 91-468 Wallace 9224 Levy 92130 Ashton et a1. 92-24 Erson 92130 Greer et a1. 137-490 Teske 91468 Driskel et a1 9224 Tennis 137490 1 6 2,925,803 2/1960 Ottestad 91396 2,988,058 6/1961 Warnecke 91-44 3,067,726 12/1962 Williams 91396 5 FOREIGN PATENTS 573,033 11/ 1945 Great Britain.

SAMUEL LEVINE, Primary Examiner.

10 FRED E. ENGELTHALER, Examiner.

P. E. MASLOUSKY, Assistant Examiner. 

1. A FLUID OPERATED CYLINDER COMPRISING, IN COMBINATION, A TUBE, A FIRST HEAD SEALINGLY MOUNTED ON ONE END OF SAID TUBE, SAID HEAD HAVING A FLOW PATH FOR A FLUID THERETHROUGH, A VALVE SLEEVE HAVING ON END CONNECTED TO THE FIRST HEAD IN COMMUNICATION WITH THE FLOW PATH IN SAID HEAD, SAID VALVE SLEEVE HAVING AN ESCAPE PORT IN ONE END ADJACENT TO THE FIRST HEAD, A VALVE TOP SEALINGLY ENGAGEABLE WITH THE OTHER END OF THE VALVE SLEEVE, SAID VALVE TOP HAVING AN APERTURE CONTAINING THEREIN FOR CONNECTION TO A FLUID SOURCE, A SLIDING VALVE BODY SEALINGLY AND SLIDEABLY MOUNTED IN THE VALVE SLEEVE, SAID VALVE BODY HAVING AN AXIAL APERTURE CONTAINED THEREIN TO ALLOW FLUID TO FLOW THROUGH THE VALVE BODY, A SEAL MOUNTED IN ONE END OF THE SLIDING VALVE BODY SEALINGLY ENGAGEABLE WITH THE FIRST HEAD, A SPRING MOUNTED IN THE VALVE SLEEVE URGING THE VALVE BODY INTO SEALING ENGAGEMENT WITH THE FIRST HEAD, A SPRING LOADED BALL CHECK MOUNTED IN THE VALVE BODY TO PREVENT FLOW OF FLUID IN A DIRECTION FROM THE FIRST HEAD TOWARD THE VALVE TOP, A SECOND HEAD MOUNTED ON THE OTHER END OF SAID TUBE, A PISTON SEALINGLY AND SLIDEABLY MOUNTED IN SAID TUBE AND BEING AXIALLY MOVABLE BETWEEN SAID HEADS, A ROD HAVING ONE END CONNECTED TO SAID PISTON AND BEING AXIALLY MOVABLE IN SAID AXIAL APERTURE OF THE FIRST HEAD, SAID ROD HAVING AN ANNULAR LOCK GROOVE FORMED IN ITS OUTER PERIPHERY, A LOCK TUBE FIXED TO THE FIRST HEAD AND BEING CONCENTRIC WITH THE ROD AND SEALINGLY AND SLIDEABLY ENGAGING THE ROD AND SEALINGLY AND SLIDEABLY ENGAGING THE LOCK TUBE, A PLURALITY OF LOCK BALLS IN ENGAGEMENT WITH THE ROD AND BEING POSITIONABLE IN THE ANNULAR LOCK GROOVE TO BE LOCKED IN SAID GROOVE BY THE LOCK SLEEVE, A LOCK SLEEVE STOP MOUNTED WITHIN THE LOCK TUBE AND BEING HELD IN ONE DIRECITON, AND A LOCK SPRING POSITIONED BETWEEN THE LOCK SLEEVE AND THE LOCK STOP CONSTANTLY URGING THE LOCK SLEEVE TOWARD THE FIRST HEAD, WHEREBY FLUID UNDER PRESSURE ENTERS THE VALVE TOP AND DISPLACES THE BALL CHECK IN THE VALVE BODY TO FLOW THROUGH THE FLUID FLOW APERTURE IN THE VALVE BODY AND PASS THROUGH THE AXIAL PATH OF THE FIRST HEAD TO APPLY A FORCE THROUGH THE AXIAL TO DISENGAGE THE LOCK BALLS AND TO APPLY A FORCE TO THE PISTON TO MOVE THE PISTON AND ROD RELATIVE TO THE HEAD, AND RELEASE OF THE PRESSURE ALLOWS PRESSURE BUILT UP IN THE TUBE TO CLOSE THE BALL CHECK VALVE AND TO MOVE THE SLIDING VALVE BODY RELATIVE TO THE VALVE SLEEVE TO ALLOW FLUID TO EXHAUST THROUGH THE EXHAUST PORT. 